Retraction on tool change
Hi All,
I'm on the end of my rope here, please help me out.
I have a self build 3D printer running Repetier firmware on a RAMPS 1.4 board. It's a rebuild/hacked/modded Leapfrog creatr dual.
So it has two E3D V6 bowden hot-ends and two extruders. The printer runs great when just using single extrusion, absolutely fabulous.
The trouble starts when I want to print with dual extrusion. I prime my extruders and start the print. After the initial homing, the printer starts. But it starts with doing a very long retraction on one of the two hot ends, usually E1 (but sometimes E0 instead). This is a problem because somehow the tip of the retracted filament expands while cooling off, so the diameter increases when pulled out of the heat break. I've noticed this behavior in both hot ends. So when the filament is recovered/extruded when starting the print, or at a tool change, it doesn't fit in the heat break anymore, resulting in a failed print...
I've spend hours and hours searching through the firmware for settings that control this behavior. I've turned off FEATURE_RETRACT and set all it's subsettings to 0, like this:
I'm on the end of my rope here, please help me out.
I have a self build 3D printer running Repetier firmware on a RAMPS 1.4 board. It's a rebuild/hacked/modded Leapfrog creatr dual.
So it has two E3D V6 bowden hot-ends and two extruders. The printer runs great when just using single extrusion, absolutely fabulous.
The trouble starts when I want to print with dual extrusion. I prime my extruders and start the print. After the initial homing, the printer starts. But it starts with doing a very long retraction on one of the two hot ends, usually E1 (but sometimes E0 instead). This is a problem because somehow the tip of the retracted filament expands while cooling off, so the diameter increases when pulled out of the heat break. I've noticed this behavior in both hot ends. So when the filament is recovered/extruded when starting the print, or at a tool change, it doesn't fit in the heat break anymore, resulting in a failed print...
I've spend hours and hours searching through the firmware for settings that control this behavior. I've turned off FEATURE_RETRACT and set all it's subsettings to 0, like this:
#define FEATURE_RETRACTION 0
#define AUTORETRACT_ENABLED 0
#define RETRACTION_LENGTH 0
#define RETRACTION_LONG_LENGTH 0
#define RETRACTION_SPEED 40
#define RETRACTION_Z_LIFT 0
#define RETRACTION_UNDO_EXTRA_LENGTH 0
#define RETRACTION_UNDO_EXTRA_LONG_LENGTH 0
#define RETRACTION_UNDO_SPEED 20
#define FILAMENTCHANGE_X_POS 0
#define FILAMENTCHANGE_Y_POS 0
#define FILAMENTCHANGE_Z_ADD 2
#define FILAMENTCHANGE_REHOME 1
#define FILAMENTCHANGE_SHORTRETRACT 0
#define FILAMENTCHANGE_LONGRETRACT 0
#define JAM_METHOD 1
#define JAM_STEPS 220
#define JAM_SLOWDOWN_STEPS 320
#define JAM_SLOWDOWN_TO 70
#define JAM_ERROR_STEPS 500
#define JAM_MIN_STEPS 10
#define JAM_ACTION 1
But the retraction still occurs! I'm all out of ideas!
Turning G92 off in S3D has no effect.
I have not tool change scripts and my start script is the bare minimum.
All tool change retraction settings in S3D have been set to 0.
Nothing works...
Please help, I do not want the printer to retract the filament in either extruder at the start of a print, or a tool change during a print, or at least not 15cm of retraction, 2mm is enough!
How can I fix this?
But the retraction still occurs! I'm all out of ideas!
Turning G92 off in S3D has no effect.
I have not tool change scripts and my start script is the bare minimum.
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 F{travel_speed}
M117 Behold: magic...
All tool change retraction settings in S3D have been set to 0.
Nothing works...
Please help, I do not want the printer to retract the filament in either extruder at the start of a print, or a tool change during a print, or at least not 15cm of retraction, 2mm is enough!
How can I fix this?
Comments
Thank you for that very usefull information! It helped me solve the problem